1. Field of the Invention
The subject invention relates to tape driving methods and apparatus, to tape transports, to information recording methods and apparatus employing recording tape or tape-like recording media, and to magnetic tape recording methods and apparatus.
2. Disclosure Statement
The following disclosure statement is made pursuant to the duty of disclosure imposed by law and formulated in 37 CFR 1.56(a). No representation is hereby made that information thus disclosed in fact constitutes prior art, inasmuch as 37 CFR 1.56(a) relies on a materiality concept which depends on uncertain and inevitably subjective elements of substantial likelihood and reasonableness, and inasmuch as a growing attitude appears to require citation of material which might lead to a discovery of pertinent material though not necessarily being of itself pertinent. Also, the following comments contain conclusions and observations which have only been drawn or become apparent after conception of the subject invention or which contrast the subject invention or its merits against the background of developments subsequent in time or priority.
In magnetic tape recording, in information recording on tape-like media, and in other fields where tape is being advanced, there are many instances where the tape is driven relative to a surface and is tensioned into engagement with such surface. In such instances, the danger arises that the tensioned tape binds to the particular surface when the advancing tape is stopped. This frequently renders it difficult to restart the tape, especially if it has been stopped for a longer period of time.
By way of example, the surface in question may be the surface of a slant track recording scanner, of a recording or playback head, of a tape guide or of another object in the tape path which is engaged by the tape.
In systems which wind the tape from and onto tape reels and employ reel drive motors for this purpose, the tape may be detensioned or slackened from the particular surface by rotation of one of the reel drive motors in a reverse direction until the tape is no longer in contact with that surface. However, such technique is not feasible with tape transports that lack individual reel drive motors or that lack a servo system capable of detensioning the tape without running up an excessive tape slack.